Control overhead reduction for low latency communication systems

ABSTRACT

The present disclosure relates to reducing control overhead in a wireless communication system. For example, a network entity may determine to transmit data according to a codeword format based on at least one of a transmission time interval (TTI), or a traffic type of the data, or any combination thereof, and configure the data for transmission on a communication channel according to the codeword format. Further, for instance, a user equipment may receive a transmission from a network entity on a downlink communication channel according to a codeword format, and transmit at least one of an acknowledgement (ACK) or a negative acknowledgement (NACK) on an uplink communication channel in response to receiving the transmission from the network entity.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit of U.S. Provisional Application Ser.No. 62/458,399, entitled “CONTROL OVERHEAD REDUCTION FOR LOW LATENCYCOMMUNICATION SYSTEMS” and filed on Feb. 13, 2017, which is expresslyincorporated by reference herein in its entirety.

BACKGROUND

Aspects of the present disclosure relate generally to wirelesscommunication networks, and more particularly, to reducing controloverhead in new radio wireless communication systems.

Wireless communication networks are widely deployed to provide varioustypes of communication content such as voice, video, packet data,messaging, broadcast, and so on. These systems may be multiple-accesssystems capable of supporting communication with multiple users bysharing the available system resources (e.g., time, frequency, andpower). Examples of such multiple-access systems include code-divisionmultiple access (CDMA) systems, time-division multiple access (TDMA)systems, frequency-division multiple access (FDMA) systems, orthogonalfrequency-division multiple access (OFDMA) systems, and single-carrierfrequency division multiple access (SC-FDMA) systems.

These multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent wireless devices to communicate on a municipal, national,regional, and even global level. For example, a fifth generation (5G)wireless communications technology (which can be referred to as newradio (NR)) is envisaged to expand and support diverse usage scenariosand applications with respect to current mobile network generations. Inan aspect, 5G communications technology can include: enhanced mobilebroadband addressing human-centric use cases for access to multimediacontent, services and data; ultra-low latency (ULL) and/orultra-reliable-low latency communications (URLLC) with certainspecifications for latency and reliability; and massive machine typecommunications, which can allow a very large number of connected devicesand transmission of a relatively low volume of non-delay-sensitiveinformation. As the demand for mobile broadband access continues toincrease, however, further improvements in NR communications technologyand beyond may be desired.

For example, for NR communications technology and beyond, controloverhead may inhibit a desired level of speed or customization forefficient operation. Thus, improvements in wireless communicationoperations may be desired.

SUMMARY

The following presents a simplified summary of one or more aspects inorder to provide a basic understanding of such aspects. This summary isnot an extensive overview of all contemplated aspects, and is intendedto neither identify key or critical elements of all aspects nordelineate the scope of any or all aspects. Its sole purpose is topresent some concepts of one or more aspects in a simplified form as aprelude to the more detailed description that is presented later.

In an aspect, the present disclosure includes a method for wirelesscommunications at a network entity. The method may include determiningto transmit data according to a codeword format based on at least one ofa transmission time interval (TTI), or a traffic type of the data, orany combination thereof. Further, the method may include configuring thedata for transmission on a communication channel according to thecodeword format. The method may include transmitting the data on thecommunication channel.

In another aspect, a network entity comprises a memory and at least oneprocessor in communication with the memory. The at least one processormay be configured to determine to transmit data according to a codewordformat based on at least one of a TTI, or a traffic type of the data, orany combination thereof. The at least one processor may further beconfigured to configure the data for transmission on a communicationchannel according to the codeword format and transmit the data on thecommunication channel.

In an additional aspect, an apparatus for wireless communications at anetwork entity may include means for determining to transmit dataaccording to a codeword format based on at least one of a TTI, or atraffic type of the data, or any combination thereof. The apparatus mayfurther include means for configuring the data for transmission on acommunication channel according to the codeword format and means fortransmitting the data on the communication channel.

In yet another aspect, a computer-readable medium storing computer codeexecutable by a processor for wireless communications at a networkentity may include code for determining to transmit data according to acodeword format based on at least one of a TTI, or a traffic type of thedata, or any combination thereof. The computer-readable medium mayfurther include code for configuring the data for transmission on acommunication channel according to the codeword format, and code fortransmitting the data on the communication channel.

In an aspect, the present disclosure includes a method for wirelesscommunications at a user equipment. The method may include receiving atransmission from a network entity on a downlink communication channelaccording to one of a first codeword format or a second codeword format,the first codeword format and the second codeword format dependent on atleast one of a TTI, or a traffic type of the data, or any combinationthereof. The method may further include transmitting at least one of anacknowledgement (ACK) or a negative acknowledgement (NACK) on an uplinkcommunication channel in response to receiving the transmission from thenetwork entity.

In another aspect, a user equipment (UE) comprises a memory and at leastone processor in communication with the memory. The at least oneprocessor may be configured to receive a transmission from a networkentity on a downlink communication channel according to a codewordformat, the codeword format dependent on at least one of a TTI, or atraffic type of the data, or any combination thereof. The at least oneprocessor may further be configured to transmit at least one of an ACKor a NACK on an uplink communication channel in response to receivingthe transmission from the network entity.

In an additional aspect, an apparatus for wireless communications at auser equipment may include means for receiving a transmission from anetwork entity on a downlink communication channel according to acodeword format, the codeword format dependent on at least one of a TTI,or a traffic type of the data, or any combination thereof. The apparatusmay further include means for transmitting at least one of an ACK or aNACK on an uplink communication channel in response to receiving thetransmission from the network entity.

In yet another aspect, a computer-readable medium storing computer codeexecutable by a processor for wireless communications at a userequipment may include code for receiving a transmission from a networkentity on a downlink communication channel according to a codewordformat, the codeword format dependent on at least one of a TTI, or atraffic type of the data, or any combination thereof. Thecomputer-readable medium may further include code for transmitting atleast one of an ACK or a NACK on an uplink communication channel inresponse to receiving the transmission from the network entity.

Moreover, the present disclosure also includes an apparatus havingcomponents or configured to execute or means for executing theabove-described methods, and a computer-readable medium storing one ormore codes executable by a processor to perform the above-describedmethods.

To the accomplishment of the foregoing and related ends, the one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative featuresof the one or more aspects. These features are indicative, however, ofbut a few of the various ways in which the principles of various aspectsmay be employed, and this description is intended to include all suchaspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed aspects will hereinafter be described in conjunction withthe appended drawings, provided to illustrate and not to limit thedisclosed aspects, wherein like designations denote like elements, andin which:

FIG. 1 is a schematic diagram of a wireless communication networkincluding at least one base station having an codeword format componentconfigured to transmit data according to a particular codeword formatand at least one user equipment (UE) having a reception determinationcomponent configured to transmit an acknowledgement (ACK) or a negativeACK (NACK);

FIG. 2 is a flow diagram of an example of a method of wirelesscommunication at a network entity;

FIG. 3 is a flow diagram of an example of a method of wirelesscommunication at a UE;

FIG. 4 is a schematic diagram of example components of the UE of FIG. 1;and

FIG. 5 is a schematic diagram of example components of the base stationof FIG. 1.

DETAILED DESCRIPTION

Various aspects are now described with reference to the drawings. In thefollowing description, for purposes of explanation, numerous specificdetails are set forth in order to provide a thorough understanding ofone or more aspects. It may be evident, however, that such aspect(s) maybe practiced without these specific details. Additionally, the term“component” as used herein may be one of the parts that make up asystem, may be hardware, firmware, and/or software stored on acomputer-readable medium, and may be divided into other components.

The present disclosure generally relates to reducing control overhead innew radio wireless communication systems. Specifically, in low latencycommunication systems such as LTE ULL and/or LTE URLLC, a relativelyshort packet may be transmitted with a small latency. For example, inLTE URLLC, a 32 byte packet may be transmitted having a 1 millisecond(ms) end-to-end latency (e.g., between transmitter and receiver). Insuch communication systems, the control overhead may impact the latencysuch that an increase in the control overhead may correspondinglyincrease the latency and hence reduce communicationefficiency/performance. As such, overhead reduction may be desirable innew radio wireless communication systems to reduce latency.

In some legacy communication system (e.g., LTE), with each subframe, upto two codewords (CW) per or for each transport block (TB) may bescheduled for transmission. That is, each codeword may be mapped to oneTB. A codeword may be a distinct stream of data to be transmitted on aphysical channel. In particular, downlink control information (DCI) mayinclude or otherwise indicate one or more parameters relating to amodulation and coding scheme (MCS), a redundancy version (RV), and/or anew data indicator (NDI) in each of the two CWs. For instance, for eachCW, a 5 bit MCS indication, a 2 bit RV indication, and a 1 bit NDIindication may be accommodated or included within the DCI. Accordingly,16 bits may be utilized to transmit two CWs. Further, in the uplink, 2bits may be utilized to transmit acknowledgment (ACK) or negativeacknowledgement (NACK) for each CW over each configured componentcarrier (CC). Hence, applying the foregoing legacy transmissionstructure in low latency communication systems would not be desirable asthe control overhead would remain quite high. Rather, it would bedesirable to reduce the control overhead for both uplink and downlinkcommunication in latency communication systems.

As such, the present aspects may provide control overhead reduction onboth the downlink and the uplink. For example, in an aspect, a networkentity may determine to transmit data according to a codeword formatbased on at least one of a transmission time interval (TTI), or atraffic type of the data, or any combination thereof. The network entitymay further configure the data for transmission on a communicationchannel according to the codeword format and proceed to transmit thedata on the communication channel. Additionally, in an aspect, a userequipment (UE) may receive a transmission from the network entity on adownlink communication channel according to the codeword format, andbased on whether the data was received, may transmit at least one of anacknowledgement (ACK) or a negative acknowledgement (NACK) on an uplinkcommunication channel. As such, the codeword format may indicate to thenetwork entity and/or the UE an amount of overhead (e.g., MCS, RV,and/or NDI) to be included within or as part of each codeword and/or anacknowledgment structure on an uplink.

Additional features of the present aspects are described in more detailbelow with respect to FIGS. 1-5.

It should be noted that the techniques described herein may be used forvarious wireless communication networks such as CDMA, TDMA, FDMA, OFDMA,SC-FDMA, and other systems. The terms “system” and “network” are oftenused interchangeably. A CDMA system may implement a radio technologysuch as CDMA2000, Universal Terrestrial Radio Access (UTRA), etc.CDMA2000 covers IS-2000, IS-95, and IS-856 standards. IS-2000 Releases 0and A are commonly referred to as CDMA2000 1×, 1×, etc. IS-856 (TIA-856)is commonly referred to as CDMA2000 1×EV-DO, High Rate Packet Data(HRPD), etc. UTRA includes Wideband CDMA (WCDMA) and other variants ofCDMA. A TDMA system may implement a radio technology such as GlobalSystem for Mobile Communications (GSM). An OFDMA system may implement aradio technology such as Ultra Mobile Broadband (UMB), Evolved UTRA(E-UTRA), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20,Flash-OFDM™, etc. UTRA and E-UTRA are part of Universal MobileTelecommunication System (UMTS). 3GPP Long Term Evolution (LTE) andLTE-Advanced (LTE-A) are new releases of UMTS that use E-UTRA. UTRA,E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from anorganization named “3rd Generation Partnership Project” (3GPP). CDMA2000and UMB are described in documents from an organization named “3rdGeneration Partnership Project 2” (3GPP2). The techniques describedherein may be used for the systems and radio technologies mentionedabove as well as other systems and radio technologies, includingcellular (e.g., LTE) communications over a shared radio frequencyspectrum band. The description below, however, describes an LTE/LTE-Asystem for purposes of example, and LTE terminology is used in much ofthe description below, although the techniques are applicable beyondLTE/LTE-A applications (e.g., to 5G networks or other next generationcommunication systems).

The following description provides examples, and is not limiting of thescope, applicability, or examples set forth in the claims. Changes maybe made in the function and arrangement of elements discussed withoutdeparting from the scope of the disclosure. Various examples may omit,substitute, or add various procedures or components as appropriate. Forinstance, the methods described may be performed in an order differentfrom that described, and various steps may be added, omitted, orcombined. Also, features described with respect to some examples may becombined in other examples.

Referring to FIG. 1, in accordance with various aspects of the presentdisclosure, an example wireless communication network 100 may include atleast one UE 110 with a modem 140 having a reception determinationcomponent 150 that determines whether an acknowledgment (ACK) or anegative acknowledgment (NACK) may be transmitted in response toreceiving data transmitted according to a codeword format on a downlinkcommunication channel. Further, wireless communication network 100 mayinclude at least one base station 105 with a modem 160 having a codewordformat component 170 that determines to transmit data according to acodeword format (e.g., first codeword format 174 or a second codewordformat 176) based on, for example, a transmission time interval (TTI)and/or traffic type of the data.

Thus, according to the present disclosure, to reduce overhead in LTEURLLC, the codeword format component 170 may limit a number of codewordsto a single codeword according to the first codeword format 174. Acodeword format may be a data structure having a given overhead. Thatis, a single set of TB related information including a single set ofMCS, RV, and/or NDI information may be included as part of the DCI. Assuch, using the first codeword format 174, the control overhead may bereduced by 8 bits as a single set of MCS, RV, and/or NDI information isincluded as part of the codeword transmission. Further, codeword formatcomponent 170 may format and/or configure transmissions according to thesecond codeword format 176, which particularly reduce overhead in LTEULL. For example, the second codeword format 176 may include one or twocodewords. To reduce overhead using two codewords according to thesecond codeword format 176, however, codeword format component 170 maytransmit a shared NDI with ACK/NACK bundling (e.g., resulting in 1 bitoverhead reduction), a shared RV across both codewords (e.g., resultingin 2 bit overhead reduction), and the same MCS for both codewords (e.g.,resulting in 5 bit overhead reduction). In some aspects, the shared RVmay be shared across both codewords as a result or based on using thesame NDI.

Modem 160 may also include retransmission component 172, which may beconfigured to retransmit data (e.g., codewords) in response to receivingat least one indication of a missing data from the UE 110. In someaspects, the retransmission component 172 may be configured toretransmit data in accordance with hybrid automatic repeat request(HARQ). For example, in legacy LTE, when 2 codewords are configured,their HARQ process identifier may be the same. In some aspects, due tothis constraint (e.g., imposed for overhead reduction), in the eventthat one codeword fails, the retransmission opportunity may not be usedto send the failed codeword with another codeword having a differentHARQ process identifier. Rather, only the failed codeword may beretransmitted.

Nonetheless, given that downlink HARQ may be asynchronous (e.g., doesnot follow a specific timing pattern/schedule), thetransmissions/retransmissions may be performed/completed faster viaretransmission component 172. Specifically, retransmission component 172may not only transmit/retransmit the failed codeword, but also either anew codeword or any other failed codeword having a different HARQprocess identifier. Further, in some aspects, first codeword format 174and/or second codeword format 176 may include one or more additionalbits to indicate the HARQ process identifier per codeword. Suchconfiguration may apply to LTE communication systems and/or ULLcommunication systems.

Additionally, wireless communication network 100 may further include UE110, which may in turn include reception determination component 150configured to transmit an ACK 152 or NACK 154 in response to receiving atransmission from base station 105. Specifically, in an example, UE 110may receive a transmission from the base station 105 transmittedaccording to the first codeword format 174. Based on whether UE 110received the data in its entirety (e.g., without missing packets orreception failure), UE 110 may transmit a 1 bit ACK or NACK on an uplinkcommunication channel (e.g., per carrier).

Further, UE 110 may, via ACK/NACK bundling component 158, bundleACK/NACKs across time, frequency, and/or spatial domains. Transmissionsover time and spatial domains may be correlated and hence, the losscaused by bundling may not be significant. Bundling across time may beutilized when multiple downlink shortened physical downlink sharedchannels (sPDSCHs) map to the same (shortened) physical uplink controlchannel (s)PUCCH. Bundling over frequency (e.g., different componentcarriers) may degrade system performance as one or more channels may notbe correlated over different carriers.

Accordingly, ACK/NAK bundling may be configurable via ACK/NACK bundlingcomponent 158. For example, in some aspects, with a two symbol sTTIlength/size in the downlink and a two symbol sTTI length/size in theuplink, ACK/NAK bundling may be adopted. However, there may be instanceswhere a two symbol sTTI length/size in the uplink coincides with a 1 msuplink length/size. In some cases, the sTTI on the uplink may bedropped, and the uplink control information (UCI) may be sent over thelonger uplink TTI length/size. As such, ACK/NAK bundling may not beutilized in such cases.

In some aspects, the configuration of the ACK/NAK bundling may bedependent on the sTTI length. For example, ACK/NACK bundling component158 may bundle if a two symbol uplink transmission length/size is used,yet may not bundle when a single slot sTTI length/size is utilized.Accordingly, based on a determination via reception determinationcomponent 150 that if UE 110 fails to receive the codeword(corresponding to a failure of one of the TBs), a 1 bit NACK may betransmitted to the base station 105 as the base station 105 may transmitboth codeword (or TBs) regardless. In some aspects, the aspects relatedto ACK/NACK bundling may apply to data received according to the firstcodeword format 174 and/or the second codeword format 176.

The wireless communication network 100 may include one or more basestations 105, one or more UEs 110, and a core network 115. The corenetwork 115 may provide user authentication, access authorization,tracking, internet protocol (IP) connectivity, and other access,routing, or mobility functions. The base stations 105 may interface withthe core network 115 through backhaul links 120 (e.g., S1, etc.). Thebase stations 105 may perform radio configuration and scheduling forcommunication with the UEs 110, or may operate under the control of abase station controller (not shown). In various examples, the basestations 105 may communicate, either directly or indirectly (e.g.,through core network 115), with one another over backhaul links 120(e.g., X1, etc.), which may be wired or wireless communication links.

The base stations 105 may wirelessly communicate with the UEs 110 viaone or more base station antennas. Each of the base stations 105 mayprovide communication coverage for a respective geographic coverage area130. In some examples, base stations 105 may be referred to as a basetransceiver station, a radio base station, an access point, an accessnode, a radio transceiver, a NodeB, eNodeB (eNB), gNodeB (gNB), HomeNodeB, a Home eNodeB, a relay, or some other suitable terminology. Thegeographic coverage area 130 for a base station 105 may be divided intosectors or cells making up only a portion of the coverage area (notshown). The wireless communication network 100 may include base stations105 of different types (e.g., macro base stations or small cell basestations, described below). Additionally, the plurality of base stations105 may operate according to different ones of a plurality ofcommunication technologies (e.g., 5G (New Radio or “NR”), fourthgeneration (4G)/LTE, 3G, Wi-Fi, Bluetooth, etc.), and thus there may beoverlapping geographic coverage areas 130 for different communicationtechnologies.

In some examples, the wireless communication network 100 may be orinclude one or any combination of communication technologies, includinga new radio (NR) or 5G technology, a Long Term Evolution (LTE) orLTE-Advanced (LTE-A) or MuLTEfire technology, a Wi-Fi technology, aBluetooth technology, or any other long or short range wirelesscommunication technology. In LTE/LTE-A/MuLTEfire networks, the termevolved node B (eNB) may be generally used to describe the base stations105, while the term UE may be generally used to describe the UEs 110.The wireless communication network 100 may be a heterogeneous technologynetwork in which different types of eNBs provide coverage for variousgeographical regions. For example, each eNB or base station 105 mayprovide communication coverage for a macro cell, a small cell, or othertypes of cell. The term “cell” is a 3GPP term that can be used todescribe a base station, a carrier or component carrier associated witha base station, or a coverage area (e.g., sector, etc.) of a carrier orbase station, depending on context.

A macro cell may generally cover a relatively large geographic area(e.g., several kilometers in radius) and may allow unrestricted accessby UEs 110 with service subscriptions with the network provider.

A small cell may include a relative lower transmit-powered base station,as compared with a macro cell, that may operate in the same or differentfrequency bands (e.g., licensed, unlicensed, etc.) as macro cells. Smallcells may include pico cells, femto cells, and micro cells according tovarious examples. A pico cell, for example, may cover a small geographicarea and may allow unrestricted access by UEs 110 with servicesubscriptions with the network provider. A femto cell may also cover asmall geographic area (e.g., a home) and may provide restricted accessand/or unrestricted access by UEs 110 having an association with thefemto cell (e.g., in the restricted access case, UEs 110 in a closedsubscriber group (CSG) of the base station 105, which may include UEs110 for users in the home, and the like). A micro cell may cover ageographic area larger than a pico cell and a femto cell, but smallerthan a macro cell. An eNB for a macro cell may be referred to as a macroeNB. An eNB for a small cell may be referred to as a small cell eNB, apico eNB, a femto eNB, or a home eNB. An eNB may support one or multiple(e.g., two, three, four, and the like) cells (e.g., component carriers).

The communication networks that may accommodate some of the variousdisclosed examples may be packet-based networks that operate accordingto a layered protocol stack and data in the user plane may be based onthe IP. A user plane protocol stack (e.g., packet data convergenceprotocol (PDCP), radio link control (RLC), MAC, etc.), may performpacket segmentation and reassembly to communicate over logical channels.For example, a MAC layer may perform priority handling and multiplexingof logical channels into transport channels. The MAC layer may also usehybrid automatic repeat/request (HARQ) to provide retransmission at theMAC layer to improve link efficiency. In the control plane, the RRCprotocol layer may provide establishment, configuration, and maintenanceof an RRC connection between a UE 110 and the base station 105. The RRCprotocol layer may also be used for core network 115 support of radiobearers for the user plane data. At the physical (PHY) layer, thetransport channels may be mapped to physical channels.

The UEs 110 may be dispersed throughout the wireless communicationnetwork 100, and each UE 110 may be stationary or mobile. A UE 110 mayalso include or be referred to by those skilled in the art as a mobilestation, a subscriber station, a mobile unit, a subscriber unit, awireless unit, a remote unit, a mobile device, a wireless device, awireless communications device, a remote device, a mobile subscriberstation, an access terminal, a mobile terminal, a wireless terminal, aremote terminal, a handset, a user agent, a mobile client, a client, orsome other suitable terminology. A UE 110 may be a cellular phone, asmart phone, a personal digital assistant (PDA), a wireless modem, awireless communication device, a handheld device, a tablet computer, alaptop computer, a cordless phone, a smart watch, a wireless local loop(WLL) station, an entertainment device, a vehicular component, acustomer premises equipment (CPE), or any device capable ofcommunicating in wireless communication network 100. Additionally, a UE110 may be Internet of Things (IoT) and/or machine-to-machine (M2M) typeof device, e.g., a low power, low data rate (relative to a wirelessphone, for example) type of device, that may in some aspects communicateinfrequently with wireless communication network 100 or other UEs. A UE110 may be able to communicate with various types of base stations 105and network equipment including macro eNBs, small cell eNBs, macro gNBs,small cell gNBs, relay base stations, and the like.

UE 110 may be configured to establish one or more wireless communicationlinks 135 with one or more base stations 105. The wireless communicationlinks 135 shown in wireless communication network 100 may carry uplink(UL) transmissions from a UE 110 to a base station 105, or downlink (DL)transmissions, from a base station 105 to a UE 110. The downlinktransmissions may also be called forward link transmissions while theuplink transmissions may also be called reverse link transmissions. Eachwireless communication link 135 may include one or more carriers, whereeach carrier may be a signal made up of multiple sub-carriers (e.g.,waveform signals of different frequencies) modulated according to thevarious radio technologies described above. Each modulated signal may besent on a different sub-carrier and may carry control information (e.g.,reference signals, control channels, etc.), overhead information, userdata, etc. In an aspect, the wireless communication links 135 maytransmit bidirectional communications using frequency division duplex(FDD) (e.g., using paired spectrum resources) or time division duplex(TDD) operation (e.g., using unpaired spectrum resources). Framestructures may be defined for FDD (e.g., frame structure type 1) and TDD(e.g., frame structure type 2). Moreover, in some aspects, the wirelesscommunication links 135 may represent one or more broadcast channels.

In some aspects of the wireless communication network 100, base stations105 or UEs 110 may include multiple antennas for employing antennadiversity schemes to improve communication quality and reliabilitybetween base stations 105 and UEs 110. Additionally or alternatively,base stations 105 or UEs 110 may employ multiple input multiple output(MIMO) techniques that may take advantage of multi-path environments totransmit multiple spatial layers carrying the same or different codeddata.

Wireless communication network 100 may support operation on multiplecells or carriers, a feature which may be referred to as carrieraggregation (CA) or multi-carrier operation. A carrier may also bereferred to as a component carrier (CC), a layer, a channel, etc. Theterms “carrier,” “component carrier,” “cell,” and “channel” may be usedinterchangeably herein. A UE 110 may be configured with multipledownlink CCs and one or more uplink CCs for carrier aggregation. Carrieraggregation may be used with both FDD and TDD component carriers. Thebase stations 105 and UEs 110 may use spectrum up to Y MHz (e.g., Y=5,10, 15, or 20 MHz) bandwidth per carrier allocated in a carrieraggregation of up to a total of Yx MHz (x=number of component carriers)used for transmission in each direction. The carriers may or may not beadjacent to each other. Allocation of carriers may be asymmetric withrespect to DL and UL (e.g., more or less carriers may be allocated forDL than for UL). The component carriers may include a primary componentcarrier and one or more secondary component carriers. A primarycomponent carrier may be referred to as a primary cell (PCell) and asecondary component carrier may be referred to as a secondary cell(SCell).

The wireless communications network 100 may further include basestations 105 operating according to Wi-Fi technology, e.g., Wi-Fi accesspoints, in communication with UEs 110 operating according to Wi-Fitechnology, e.g., Wi-Fi stations (STAs) via communication links in anunlicensed frequency spectrum (e.g., 5 GHz). When communicating in anunlicensed frequency spectrum, the STAs and AP may perform a clearchannel assessment (CCA) or listen before talk (LBT) procedure prior tocommunicating in order to determine whether the channel is available.

Additionally, one or more of base stations 105 and/or UEs 110 mayoperate according to a NR or 5G technology referred to as millimeterwave (mmW or mmwave) technology. For example, mmW technology includestransmissions in mmW frequencies and/or near mmW frequencies. Extremelyhigh frequency (EHF) is part of the radio frequency (RF) in theelectromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and awavelength between 1 millimeter and 10 millimeters. Radio waves in thisband may be referred to as a millimeter wave. Near mmW may extend downto a frequency of 3 GHz with a wavelength of 100 millimeters. Forexample, the super high frequency (SHF) band extends between 3 GHz and30 GHz, and may also be referred to as centimeter wave. Communicationsusing the mmW and/or near mmW radio frequency band has extremely highpath loss and a short range. As such, base stations 105 and/or UEs 110operating according to the mmW technology may utilize beamforming intheir transmissions to compensate for the extremely high path loss andshort range.

Referring to FIG. 2, for example, a method 300 of wireless communicationin operating a network entity such as base station 105 according to theabove-described aspects to provide control overhead reduction a newradio environment includes one or more of the herein-defined actions.The blocks illustrated as having dashed lines may be optional.

At block 302, the method 300 may determine to transmit data according toa codeword format based on at least one of a TTI, or a traffic type ofthe data, or any combination thereof. For example, in an aspect, basestation 105 may execute codeword format component 170 to determine totransmit data according to a codeword format (e.g., first codewordformat 174 or a second codeword format 176) based on at least one of aTTI (e.g., TTI length), or a traffic type of the data, or anycombination thereof.

In some aspects, the first codeword format 174 may include a singlecodeword having a single set of at least one of a MCS, a RV, or a NDIwithin DCI. Further, in some aspects, the traffic type may correspondsto URLLC (e.g., in the case of the first codeword format 174).

In some aspects, the second codeword format 176 may include twocodewords having a single MCS, a single RV, and/or a single NDI sharedacross the two codewords. Further, the TTI may correspond to an sTTI.Additionally, the traffic type may correspond to LTE ULL communications(e.g., in the case of the first codeword format 176).

At block 304, the method 300 may configure the data for transmission ona communication channel according to the codeword format. For example,in an aspect, base station 105 may execute codeword format component 170to configure the data for transmission on a communication channelaccording to the codeword format (e.g., first codeword format 174 or thesecond codeword format 176).

At block 306, the method 300 may transmit the data on the communicationchannel. For example, in an aspect, base station 105 may execute modem160 to transmit the data on the communication channel.

Further, in some aspects, the transmitted data may be associated with atleast one codeword. Although not shown, method 300 may receive, on anuplink communication channel, a NACK 154 indicating receipt failure ofthe at least one codeword, and transmit, according to codeword format(e.g., first codeword format 174 or the second codeword format 176), theat least one codeword and an additional codeword corresponding to a newcodeword transmission or a failed codeword transmission having adistinct HARQ process identifier. In some aspects, the new HARQidentifier may be included in the DCI.

In some aspects, configuring the data for transmission on thecommunication channel according to the codeword format may includedetermining whether the codeword format corresponds to a single codewordassociated with the sTTI or two codewords, bundling the data fortransmission based on determining that the codeword format correspondsto the two codewords, and forgoing bundling of the data for transmissionbased on determining that the codeword format corresponds to the singlecodeword associated with the sTTI.

Referring to FIG. 3, for example, a method 400 of wireless communicationin operating UE 110 according to the above-described aspects to transmitat least one ACK or NACK in response to receiving data according to acodeword format includes one or more of the herein-defined actions. Theblocks illustrated as having dashed lines may be optional.

At block 402, the method 400 may receive a transmission from a networkentity on a downlink communication channel according to a codewordformat, the codeword format dependent on at least one of a TTI, or atraffic type of the data, or any combination thereof. For example, theUE 110 and/or modem 140 may execute reception determination component150 to receive a transmission from a network entity (e.g., base station105) on a downlink communication channel according to a codeword format(e.g., first codeword format 174 or a second codeword format 176), thecodeword format dependent on at least one of a TTI, or a traffic type ofthe data, or any combination thereof.

At block 404, the method 400 may transmit at least one of an ACK or aNACK on an uplink communication channel in response to receiving thetransmission from the network entity. For instance, the UE 110 and/ormodem 140 may execute reception determination component 150 to transmitat least one of an ACK 152 or a NACK 154 on an uplink communicationchannel in response to receiving the transmission from the networkentity.

In some aspects, the second codeword format may include two codewords.Although not shown, method 400 may, via ACK/NACK bundling component 158,detect a single NDI across the two codewords and determine, via ACK/NACKbundling component 158, reception failure of at least one TB associatedwith at least one of the codewords. Further, transmitting the at leastone of the ACK 152 or the NACK 154 may include transmitting the NACK 154based on determining reception failure of at least one transport blockassociated with at least one of the codewords.

In some aspects, although not shown, method 400 may determine, viatransmission length/size determiner 160, whether a first TTI length or asecond TTI length is to be used in transmitting on the uplinkcommunication channel. In some aspects, transmitting the at least one ofthe ACK 152 or the NACK 154 may include transmitting the at least one ofthe ACK 152 or the NACK 154 according to ACK/NACK bundling based on adetermination that the first TTI length is to be used in transmitting onthe uplink communication channel, the first TTI length corresponding totwo symbols, and foregoing transmission of the at least one of the ACK152 or the NACK 154 according to ACK/NACK bundling based on adetermination that the second TTI length is to be used in transmittingon the uplink communication channel, the second TTI length correspondingto a single slot sTTI. In some aspects, ACK/NACK bundling may beutilized when a 1 ms TTI/slot and a two symbol TTI/slot collide in theuplink.

Referring to FIG. 4, one example of an implementation of UE 110 mayinclude a variety of components, some of which have already beendescribed above, but including components such as one or more processors412 and memory 416 and transceiver 402 in communication via one or morebuses 444, which may operate in conjunction with modem 140 and receptiondetermination component 150 to enable one or more of the functionsdescribed herein related to transmitting ACKs/NACKs based on a receptionof data according to a codeword format. Further, the one or moreprocessors 412, modem 414, memory 416, transceiver 402, radio frequency(RF) front end 488 and one or more antennas 465, may be configured tosupport voice and/or data calls (simultaneously or non-simultaneously)in one or more radio access technologies. In some aspects, the modem 414may be the same as or similar to the modem 414.

In an aspect, the one or more processors 412 can include a modem 414that uses one or more modem processors. The various functions related toresource identification component 150 may be included in modem 140and/or processors 412 and, in an aspect, can be executed by a singleprocessor, while in other aspects, different ones of the functions maybe executed by a combination of two or more different processors. Forexample, in an aspect, the one or more processors 412 may include anyone or any combination of a modem processor, or a baseband processor, ora digital signal processor, or a transmit processor, or a receiverprocessor, or a transceiver processor associated with transceiver 402.In other aspects, some of the features of the one or more processors 412and/or modem 140 associated with resource identification component 150may be performed by transceiver 402.

Also, memory 416 may be configured to store data used herein and/orlocal versions of applications 475 or resource identification component150 and/or one or more of its subcomponents being executed by at leastone processor 412. Memory 416 can include any type of computer-readablemedium usable by a computer or at least one processor 412, such asrandom access memory (RAM), read only memory (ROM), tapes, magneticdiscs, optical discs, volatile memory, non-volatile memory, and anycombination thereof. In an aspect, for example, memory 416 may be anon-transitory computer-readable storage medium that stores one or morecomputer-executable codes defining resource identification component 150and/or one or more of its subcomponents, and/or data associatedtherewith, when UE 110 is operating at least one processor 412 toexecute resource identification component 150 and/or one or more of itssubcomponents.

Transceiver 402 may include at least one receiver 406 and at least onetransmitter 408. Receiver 406 may include hardware, firmware, and/orsoftware code executable by a processor for receiving data, the codecomprising instructions and being stored in a memory (e.g.,computer-readable medium). Receiver 406 may be, for example, a RFreceiver. In an aspect, receiver 406 may receive signals transmitted byat least one base station 125. Additionally, receiver 406 may processsuch received signals, and also may obtain measurements of the signals,such as, but not limited to, Ec/Io, SNR, RSRP, RSSI, etc. Transmitter408 may include hardware, firmware, and/or software code executable by aprocessor for transmitting data, the code comprising instructions andbeing stored in a memory (e.g., computer-readable medium). A suitableexample of transmitter 408 may include, but is not limited to, an RFtransmitter.

Moreover, in an aspect, UE 110 may include RF front end 488, which mayoperate in communication with one or more antennas 465 and transceiver402 for receiving and transmitting radio transmissions, for example,wireless communications transmitted by at least one base station 125 orwireless transmissions transmitted by UE 110. RF front end 488 may beconnected to one or more antennas 465 and can include one or morelow-noise amplifiers (LNAs) 490, one or more switches 492, one or morepower amplifiers (PAs) 498, and one or more filters 496 for transmittingand receiving RF signals.

In an aspect, LNA 490 can amplify a received signal at a desired outputlevel. In an aspect, each LNA 490 may have a specified minimum andmaximum gain values. In an aspect, RF front end 488 may use one or moreswitches 492 to select a particular LNA 490 and its specified gain valuebased on a desired gain value for a particular application.

Further, for example, one or more PA(s) 498 may be used by RF front end488 to amplify a signal for an RF output at a desired output powerlevel. In an aspect, each PA 498 may have specified minimum and maximumgain values. In an aspect, RF front end 488 may use one or more switches492 to select a particular PA 498 and a corresponding specified gainvalue based on a desired gain value for a particular application.

Also, for example, one or more filters 496 can be used by RF front end488 to filter a received signal to obtain an input RF signal. Similarly,in an aspect, for example, a respective filter 496 can be used to filteran output from a respective PA 498 to produce an output signal fortransmission. In an aspect, each filter 496 can be connected to aspecific LNA 490 and/or PA 498. In an aspect, RF front end 488 can useone or more switches 492 to select a transmit or receive path using aspecified filter 496, LNA 490, and/or PA 498, based on a configurationas specified by transceiver 402 and/or processor 412.

As such, transceiver 402 may be configured to transmit and receivewireless signals through one or more antennas 465 via RF front end 488.In an aspect, transceiver may be tuned to operate at specifiedfrequencies such that UE 110 can communicate with, for example, one ormore base stations 125 or one or more cells associated with one or morebase stations 125. In an aspect, for example, modem 140 can configuretransceiver 402 to operate at a specified frequency and power levelbased on the UE configuration of the UE 110 and the communicationprotocol used by modem 140.

In an aspect, modem 140 can be a multiband-multimode modem, which canprocess digital data and communicate with transceiver 402 such that thedigital data is sent and received using transceiver 402. In an aspect,modem 140 can be multiband and be configured to support multiplefrequency bands for a specific communications protocol. In an aspect,modem 140 can be multimode and be configured to support multipleoperating networks and communications protocols. In an aspect, modem 140can control one or more components of UE 110 (e.g., RF front end 488,transceiver 402) to enable transmission and/or reception of signals fromthe network based on a specified modem configuration. In an aspect, themodem configuration can be based on the mode of the modem and thefrequency band in use. In another aspect, the modem configuration can bebased on UE configuration information associated with UE 110 as providedby the network during cell selection and/or cell reselection.

Referring to FIG. 5, one example of an implementation of base station105 may include a variety of components, some of which have already beendescribed above, but including components such as one or more processors512, a memory 516, and a transceiver 502 in communication via one ormore buses 544, which may operate in conjunction with modem 160 andcodeword format component 170 to enable one or more of the functionsdescribed herein relating to transmitting data according to determinedcodeword formats.

The transceiver 502, receiver 506, transmitter 508, one or moreprocessors 512, memory 516, applications 575, buses 544, RF front end588, LNAs 590, switches 592, filters 596, PAs 598, and one or moreantennas 565 may be the same as or similar to the correspondingcomponents of UE 110, as described above, but configured or otherwiseprogrammed for base station operations as opposed to UE operations.

The above detailed description set forth above in connection with theappended drawings describes examples and does not represent the onlyexamples that may be implemented or that are within the scope of theclaims. The term “example,” when used in this description, means“serving as an example, instance, or illustration,” and not “preferred”or “advantageous over other examples.” The detailed description includesspecific details for the purpose of providing an understanding of thedescribed techniques. These techniques, however, may be practicedwithout these specific details. In some instances, well-known structuresand apparatuses are shown in block diagram form in order to avoidobscuring the concepts of the described examples.

Information and signals may be represented using any of a variety ofdifferent technologies and techniques. For example, data, instructions,commands, information, signals, bits, symbols, and chips that may bereferenced throughout the above description may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, computer-executable code or instructionsstored on a computer-readable medium, or any combination thereof.

The various illustrative blocks and components described in connectionwith the disclosure herein may be implemented or performed with aspecially-programmed device, such as but not limited to a processor, adigital signal processor (DSP), an ASIC, a FPGA or other programmablelogic device, a discrete gate or transistor logic, a discrete hardwarecomponent, or any combination thereof designed to perform the functionsdescribed herein. A specially-programmed processor may be amicroprocessor, but in the alternative, the processor may be anyconventional processor, controller, microcontroller, or state machine. Aspecially-programmed processor may also be implemented as a combinationof computing devices, e.g., a combination of a DSP and a microprocessor,multiple microprocessors, one or more microprocessors in conjunctionwith a DSP core, or any other such configuration.

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on anon-transitory computer-readable medium. Other examples andimplementations are within the scope and spirit of the disclosure andappended claims. For example, due to the nature of software, functionsdescribed above can be implemented using software executed by aspecially programmed processor, hardware, firmware, hardwiring, orcombinations of any of these. Features implementing functions may alsobe physically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations. Also, as used herein, including in the claims, “or” as usedin a list of items prefaced by “at least one of” indicates a disjunctivelist such that, for example, a list of “at least one of A, B, or C”means A or B or C or AB or AC or BC or ABC (i.e., A and B and C).

Computer-readable media includes both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. A storage medium may be anyavailable medium that can be accessed by a general purpose or specialpurpose computer. By way of example, and not limitation,computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or otheroptical disk storage, magnetic disk storage or other magnetic storagedevices, or any other medium that can be used to carry or store desiredprogram code means in the form of instructions or data structures andthat can be accessed by a general-purpose or special-purpose computer,or a general-purpose or special-purpose processor. Also, any connectionis properly termed a computer-readable medium. For example, if thesoftware is transmitted from a website, server, or other remote sourceusing a coaxial cable, fiber optic cable, twisted pair, digitalsubscriber line (DSL), or wireless technologies such as infrared, radio,and microwave, then the coaxial cable, fiber optic cable, twisted pair,DSL, or wireless technologies such as infrared, radio, and microwave areincluded in the definition of medium. Disk and disc, as used herein,include compact disc (CD), laser disc, optical disc, digital versatiledisc (DVD), floppy disk and Blu-ray disc where disks usually reproducedata magnetically, while discs reproduce data optically with lasers.Combinations of the above are also included within the scope ofcomputer-readable media.

The previous description of the disclosure is provided to enable aperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the common principles defined herein may beapplied to other variations without departing from the spirit or scopeof the disclosure. Furthermore, although elements of the describedaspects and/or embodiments may be described or claimed in the singular,the plural is contemplated unless limitation to the singular isexplicitly stated. Additionally, all or a portion of any aspect and/orembodiment may be utilized with all or a portion of any other aspectand/or embodiment, unless stated otherwise. Thus, the disclosure is notto be limited to the examples and designs described herein but is to beaccorded the widest scope consistent with the principles and novelfeatures disclosed herein.

What is claimed is:
 1. A method of wireless communications at a networkentity, comprising: determining to transmit data according to a codewordformat corresponding to a single codeword for downlink communicationbased on at least a length of a transmission time interval (TTI);configuring the data for transmission on a downlink communicationchannel according to the codeword format; and transmitting the data onthe downlink communication channel.
 2. The method of claim 1, whereinthe single codeword includes a single set of at least one of amodulation and code scheme (MCS), a redundancy version (RV), or a newdata indicator (NDI) within downlink control information (DCI).
 3. Themethod of claim 2, wherein determining to transmit data according to thecodeword format is further based on a traffic type, the traffic typecorresponding to Ultra Reliable Low Latency Communication (URLLC). 4.The method of claim 1, further comprising: receiving, on an uplinkcommunication channel, a negative acknowledgement (NACK) indicatingreceipt failure of the single codeword; and transmitting, according tothe codeword format, the single codeword and an additional codewordcorresponding to a new codeword transmission or a failed codewordtransmission having a distinct hybrid automatic repeat request (HARQ)process identifier.
 5. The method of claim 1, wherein the TTIcorresponds to a shortened TTI (sTTI).
 6. The method of claim 5, whereinconfiguring the data for transmission on the communication channelaccording to the codeword format includes: determining that the codewordformat corresponds to the single codeword associated with the sTTI; andforgoing bundling of the data for transmission based on determining thatthe codeword format corresponds to the single codeword associated withthe sTTI.
 7. The method of claim 1, wherein determining to transmit dataaccording to the codeword format is further based on a traffic type, thetraffic type corresponding to LTE Ultra Low Latency (ULL)communications.
 8. The method of claim 1, wherein determining totransmit data according to the codeword format includes determining totransmit data in a new radio wireless communication system according tothe codeword format corresponding to the single codeword to reducelatency for short packet transmissions.
 9. A method of wirelesscommunications at a user equipment, comprising: receiving a transmissionfrom a network entity on a downlink communication channel according to acodeword format corresponding to a single codeword for downlinkcommunication, the codeword format dependent on at least a length of atransmission time interval (TTI); and transmitting at least one of anacknowledgement (ACK) or a negative acknowledgement (NACK) on an uplinkcommunication channel in response to receiving the transmission from thenetwork entity.
 10. The method of claim 9, further comprising: detectinga single new data indicator (NDI) associated with the single codeword;and determining reception failure of at least one transport blockassociated with at least one of a number of codewords, whereintransmitting the at least one of the ACK or the NACK includestransmitting the NACK based on determining reception failure of at leastone transport block associated with at least one of the number ofcodewords.
 11. The method of claim 9, further comprising determiningwhether a first TTI length or a second TTI length is to be used intransmitting on the uplink communication channel, wherein transmittingthe at least one of the ACK or the NACK includes: transmitting the atleast one of the ACK or the NACK according to ACK/NACK bundling based ona determination that the first TTI length is to be used in transmittingon the uplink communication channel; and foregoing transmission of theat least one of the ACK or the NACK according to ACK/NACK bundling basedon a determination that the second TTI length is to be used intransmitting on the uplink communication channel.
 12. A network entity,comprising: a memory; and at least one processor in communication withthe memory and configured to: determine to transmit data according to acodeword format corresponding to a single codeword for downlinkcommunication based on at least a length of a transmission time interval(TTI); configure the data for transmission on a downlink communicationchannel according to the codeword format; and transmit the data on thedownlink communication channel.
 13. The network entity of claim 12,wherein the single codeword includes a single set of at least one of amodulation and code scheme (MCS), a redundancy version (RV), or a newdata indicator (NDI) within downlink control information (DCI).
 14. Thenetwork entity of claim 13, wherein the at least one processor isfurther configured to determine to transmit the codeword format based ona traffic type, the traffic type corresponding to Ultra Reliable LowLatency Communication (URLLC).
 15. The network entity of claim 12,wherein the at least one processor is further configured to: receive, onan uplink communication channel, a negative acknowledgement (NACK)indicating receipt failure of the single codeword; and transmit,according to the codeword format, the single codeword and an additionalcodeword corresponding to a new codeword transmission or a failedcodeword transmission having a distinct hybrid automatic repeat request(HARQ) process identifier.
 16. The network entity of claim 12, whereinthe TTI corresponds to a shortened TTI (sTTI).
 17. The network entity ofclaim 16, wherein to configure the data for transmission on thecommunication channel according to the codeword format, the at least oneprocessor is further configured to: determine that the codeword formatcorresponds to the single codeword associated with the sTTI; and forgobundling of the data for transmission based on determining that thecodeword format corresponds to the single codeword associated with thesTTI.
 18. The network entity of claim 12, wherein the at least oneprocessor is further configured to determine to transmit the codewordformat based on a traffic type, the traffic type corresponding to LTEUltra Low Latency (ULL) communications.
 19. The method of claim 9,wherein the single codeword includes a single set of at least one of amodulation and code scheme (MCS), a redundancy version (RV), or a newdata indicator (NDI) within downlink control information (DCI).
 20. Auser equipment (UE), comprising: a memory; and at least one processor incommunication with the memory and configured to: receive a transmissionfrom a network entity on a downlink communication channel according to acodeword format corresponding to a single codeword for downlinkcommunication, the codeword format dependent on at least a length of atransmission time interval (TTI); and transmit at least one of anacknowledgement (ACK) or a negative acknowledgement (NACK) on an uplinkcommunication channel in response to receiving the transmission from thenetwork entity.
 21. The UE of claim 20, the at least one processorfurther configured to: detect a single new data indicator (NDI)associated with the single codeword; and determine reception failure ofat least one transport block associated with at least one of a number ofcodewords, wherein to transmit the at least one of the ACK or the NACK,the at least one processor is further configured to transmit the NACKbased on determining reception failure of at least one transport blockassociated with at least one of the number of codewords.
 22. The UE ofclaim 20, wherein the at least one processor is further configured todetermine whether a first TTI length or a second TTI length is to beused in transmitting on the uplink communication channel, wherein totransmit the at least one of the ACK or the NACK, the at least oneprocessor is further configured to: transmit the at least one of the ACKor the NACK according to ACK/NACK bundling based on a determination thatthe first TTI length is to be used in transmitting on the uplinkcommunication channel; and forgo transmission of the at least one of theACK or the NACK according to ACK/NACK bundling based on a determinationthat the second TTI length is to be used in transmitting on the uplinkcommunication channel.
 23. An apparatus for wireless communications,comprising: means for determining to transmit data according to acodeword format corresponding to a single codeword for downlinkcommunication based on at least a length of a transmission time interval(TTI); means for configuring the data for transmission on a downlinkcommunication channel according to the codeword format; and means fortransmitting the data on the downlink communication channel.